Microbial coating of controlled-release fertilizers

Abstract

Compositions including a core particle including at least one fertilizer nutrient and a shell substantially covering the core particle, wherein the shell includes at least one polymer layer or wax layer and one or more species of microbes (such as a population of cells from at least one species of microbes) are provided. In some embodiments, at least one of the polymer layer and/or the wax layer includes the one or more species of microbes. In other examples, the one or more species of microbes are included between layers, for example, between two polymer layers, between two wax layers, or between a polymer layer and a wax layer. Methods of preparing the compositions are also provided. Methods of using the disclosed compositions that include contacting soil, plants, plant parts, or seeds with the composition are provided.

We claim: 
     
       1. A composition comprising:
 a core particle comprising at least one fertilizer nutrient; and 
 a shell substantially covering the core particle, wherein the shell comprises at least one polymer layer comprising polyurethane and one or more species of microbes. 
 
     
     
       2. The composition of  claim 1 , comprising two or more polyurethane and/or wax layers, wherein at least one of the polyurethane layers comprises the one or more species of microbes. 
     
     
       3. The composition of  claim 2 , wherein the composition comprises a layer of wax between two or more polyurethane layers. 
     
     
       4. The composition of  claim 1 , wherein the one or more species of microbes comprise each of  Lactobacillus delbrueckii, Virgibacillus halophilus, Azotobacter vinelandii, Clostridium pasteurianum, Paenibacillus chibensis, Streptomyces griseus, Pseudomonas sp Pseudomonas putida, Bacillus sp Bacillus amyloliquefaciens, Oceanobacillus oncorhynchi, Paenibacillus lautus Bacillus licheniformis, Lactobacillus vini, Paenibacillus cookii, Bacillus subtilis, Lactobacillus buchneri, Bacillus megaterium, Acetobacter pasteurianus, Clostridium beijerinckii, Lactobacillus casei/paracasei , and  Bacillus flexus.    
     
     
       5. The composition of  claim 4 , wherein each of the one or more species of microbes have 16S rDNA sequences having at least 99% sequence identity to one of SEQ ID NOs: 1-22. 
     
     
       6. The composition of  claim 1 , wherein the outer layer comprises the one or more species of microbes. 
     
     
       7. The composition of  claim 1 , wherein the at least one fertilizer nutrient is urea, monoammonium phosphate, diammonium phosphate, ammonium nitrate, potassium nitrate, potassium sulfate, or ammonium sulfate. 
     
     
       8. A method of making a fertilizer-microbial composition, comprising:
 contacting a core particle comprising at least one fertilizer nutrient with a mixture comprising a polyol and a diisocyanate and one or more species of microbes to form a layer substantially covering the core particle; and 
 polymerizing the polyol and diisocyanate to form a polyurethane coated core particle, wherein the polyurethane coating comprises the one or more species of microbes. 
 
     
     
       9. The method of  claim 8 , wherein the one or more species of microbes comprise each of  Lactobacillus delbrueckii, Virgibacillus halophilus, Azotobacter vinelandii, Clostridium pasteurianum, Paenibacillus chibensis, Streptomyces griseus, Pseudomonas sp. Pseudomonas putida, Bacillus sp. Bacillus amyloliquefaciens, Oceanobacillus oncorhynchi, Paenibacillus lautus Bacillus licheniformis, Lactobacillus vini, Paenibacillus cookii, Bacillus subtilis, Lactobacillus buchneri, Bacillus megaterium, Acetobacter pasteurianus, Clostridium beijerinckii, Lactobacillus casei/paracasei , and  Bacillus flexus.    
     
     
       10. The method of  claim 9 , wherein the each of the one or more species of microbes have 16S rDNA sequences having at least 99% sequence identity to one of SEQ ID NOs: 1-22. 
     
     
       11. The method of  claim 8 , wherein the at least one fertilizer nutrient is urea, monoammonium phosphate, diammonium phosphate, ammonium nitrate, potassium nitrate, potassium sulfate, or ammonium sulfate. 
     
     
       12. The method of  claim 8 , wherein the one or more species of microbes are in a liquid form. 
     
     
       13. The method of  claim 8 , wherein the one or more species of microbes are in a freeze-dried form. 
     
     
       14. The method of  claim 8 , wherein the one or more species of microbes comprise American Type Culture Collection deposit number PTA-123288, PTA-123298, PTA-123289, or a combination of two or more thereof. 
     
     
       15. The method of  claim 8 , wherein the diisocyanate is methylene diphenyl diisocyanate (MDI) or toluene diisocyanate (TDI). 
     
     
       16. A fertilizer-microbial composition made by the method of  claim 8 . 
     
     
       17. A method of making a fertilizer-microbial composition, comprising:
 (i) contacting a core particle comprising at least one fertilizer nutrient with a mixture comprising a polyol and a diisocyanate and one or more species of microbe; and polymerizing the polyol and diisocyanate to form a polyurethane layer comprising the one or more species of microbes; and 
 (ii) contacting the core particle comprising at least one fertilizer nutrient with wax to form a wax layer; 
 wherein steps (i) and (ii) may be performed in either order and/or repeated one or more times. 
 
     
     
       18. The method of  claim 17 , wherein outer layer comprises the one or more species of microbes. 
     
     
       19. The method of  claim 17 , wherein the diisocyanate is methylene diphenyl diisocyanate (MDI) or toluene diisocyanate (TDI). 
     
     
       20. A method comprising contacting soil, plants, plant parts, or seeds with the composition of  claim 1 .